Customworksking

iTrader: (74)

Green green for Tq green red is the avg setup..F's ...thou i had some luck with reedy 769's

Still Bill

iTrader: (16)

Just look a page or two back for our take on F brushes.

jgroenhof

iTrader: (3)

After One and a half heats (9 minutes), there is definetly no pitting on the comm. I will say the comm still looks pretty rough. Black, and quite worn.

I have my comms cut at the track $5 a pop. is it possible that the lathe is poor? Is the material on CO27's particularly soft? Could I be over-sprung? (766 red-/+767 purple)
Any guesses?

Still Bill

iTrader: (16)

I have been told that the on-road track at SoCal is pretty dusty after the off-road race days. Or, are you accidentally getting oil on the comm from the endbell bushing? Just guesses.

You have some top notch racers at SoCal that should be able to help you. Show your CO27 motor to them for their take on your issue.

And with brushless motors coming on strong, keep your eyes out for a good comm lathe...Cheap...If you are staying with brushed.

Bill

mxracer23

I'm hoping that someone can help me out. I have a new co27 pro that is arching the brushes so badly that it's pealing the trailing edge off of the brushes. I have had the motor in several experienced peoples hands and the comm is true hoods aligned etc. Gearing is dialed in motor comes off the track at a reasonable temp. What is everyone including myself missing here?

Could it be just a bad motor segment or speed control issue. It makes 5 minutes but the brushes should not come out pealed.

Mark

MR JOLLY

try filing the leading & trailing edge a nats ,so then the centre of brush will have a better contact with the brush
just want to take the sharp edges of the brush ,that`s all ,as they come out of the mould they leave very sharp edges.like little spikes & they cut into the comm as soon as you spin it up

mxracer23

I'll try and see if that helps to keep the brush intact. The thing that bothers me the most is that 1/4 of the bush is black on the trailing side like carbon build up

MR JOLLY

Tony
got my prices for 767`s & F-lines matey

MR JOLLY

then the brush or Hood are sitting pretty ,like the brush`s are cocked to one side
trial & error to get the brush`s sitting right

Mauri

what do you guys use to take the bushings out of the can and what do you use to polish them and the armature shafts?

MR JOLLY

i use a Kose bushing removel/inserting tool( like a mini flywheel puller realy)
Br00d does these ,be carefull when you use as you still got to make sure the bushing/bearing is seated level before pulling it in to the can/endbell other wise there be a failure in the thread stud & it will snap off


Polishing
tooth paste is really good ,since it can be washed off with water with out leaving any there & getting premature wear when motor is raced

reamers
for losening up tight fitting holes/shafts .you can get different size`s
But again be warned if you go mad with them you have premature wear on bushing & the shaft be floating around since you have made the hole to big

reoil bushings after every race ,you be suprised how much oil gets thrown off in a race & this causes vibration which makes power go soft

i use Speed lube ,it is very thin ,but it works really well
you can have thicker oil ,but your motor won`t be as free ,friction is the stocks worse enemy

HTH

BigDaddyT

Try cutting the trailing edge of the brush off a bit - I've seen a few motors like this that benefit a lot from pushing the timing forward. Also, check your spring tension and make sure it's not brush bouncing.

One other thing - check for a mushroomed comm. If you got a hard whack on the endbell from being T-boned or something, that can cause a lot of weird problems.

C_Meekhof

Do springs work together on a motor?

Colin

Still Bill

iTrader: (16)

Colin,

If I understand your question correctly...Springs work independently of each other on a motor. One spring applies inward pressure to the positive motor brush (+) and the other to the negative motor brush (-).

Bill

C_Meekhof

Thank you for the help.